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Question

If $(y + z) = 8$ and $yz = 6$, find the value of $(y - z)^2$.

This question was previously asked in
RRB NTPC 2019 CBT 1 Question Paper (8-Mar-2021) (Shift 2)
The correct answer is
40

Algebraic Solution for $(y - z)^2$

We are given the equations:

  • $ (y + z) = 8 $
  • $ yz = 6 $

We need to find the value of $ (y - z)^2 $.

Applying Algebraic Identity

We use the algebraic identity that relates $ (y + z)^2 $, $ (y - z)^2 $, and $ yz $: $ (y - z)^2 = (y + z)^2 - 4yz $

Calculation

Substitute the given values into the identity:

$ (y - z)^2 = (8)^2 - 4(6) $

$ (y - z)^2 = 64 - 24 $

$ (y - z)^2 = 40 $

Thus, the value of $ (y - z)^2 $ is 40.

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Similar Questions

  1. If $a + b + c = 10$ and $ab + bc + ca = 31$, find the value of $a^2 + b^2 + c^2$
  2. If $a + b + c = 0$, then find the value of $\frac{(a^2+b^2+c^2)^2}{a^2b^2+b^2c^2+c^2a^2}$

  3. If $x^4 + \frac{1}{x^4} = 322$, then $x^3 - \frac{1}{x^3} = ?$
  4. What is the value of the following expression:

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Important Questions from Identities

  1. (x - y) 3+ (y - z) 3+ (z - x) 3= ?

  2. If   \(x + \left( {\frac{1}{x}} \right) = 12\)  and  \({x^2} - \frac{1}{{{x^2}}} = 50\) , then the value of  \({x^4} - \frac{1}{{{x^4}}} \)  is:

  3. \((\sqrt{7} + \sqrt{9})(\sqrt{7} - \sqrt{9})\) is equal to:
  4. If x satisfies the equation x 2 - 2x + 1 = 0, then the value of  \(\rm x^3 - \frac{1}{x^3}\)  is:

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